Spreadable coiler drum

ABSTRACT

In a winder mandrel ( 1 ) with radially movable spreading segments ( 2 ) which are arranged on the periphery, a mandrel body ( 3 ) and a pulling rod ( 4 ), the spreading segments ( 2 ) and/or the mandrel body ( 3 ) and/or the pulling rod ( 4 ) are configured as magnets. 
     A method for operating a winder mandrel of this type provides for the spreading segments ( 2 ) and/or the mandrel body ( 3 ) and/or the pulling rod ( 4 ) to be configured as electromagnets, and for the supply voltage of the electromagnets to be switched on during initial winding of the beginning of the strip, lowered during the rolling and raised again when the strip is slipped out.

The invention relates to a winder mandrel with radially moveablespreading segments which are arranged on the periphery, a mandrel bodyand a pulling rod, and a method for operating such a winder mandrel.

Winder systems are used for example in order to wind rolled sheet metalor other materials into a coil on a winder mandrel and/or to unwind acoil. For winding, the spreading segments are deflected radiallyoutwards in such a manner that the outer periphery of the spreadingsegments forms a circle. In order to unwind a coil, the diameter of thewinder mandrel must become smaller than the inner diameter of the coilin order to accommodate the coil. To this end, two diameters can usuallybe produced in a winder mandrel in a targeted manner, with only aspread, maximum diameter being configured to be completely round.

In known embodiments of winder mandrels of this type, winder segmentsare deflected radially by means of wedge faces which are moved by meansof pulling or pushing rods.

DE 35 02 452 A1 describes a winding and/or unwinding winder for rolledstrips, with a drum which consists of a plurality of segments which canbe moved in a spreading manner and bear with wedge-shaped slidingsurfaces against a winder shaft which is mounted such that it can rotatein a winder housing. A punch is guided in the winder shaft, which punchis connected by means of a connecting flange to the drum segments. Anactuator effects a relative axial displacement between the winder shaftand the punch connected to the segments, by means of which displacementa spreading movement of the segments is brought about. Furthermore, thewinder has a displacing drive which effects the displacement in and outof the winder drum relative to the coil and/or the strip centreregulator, with the winder shaft being mounted in the stationary winderhousing in such a manner that it can be displaced axially, the actuatorhaving in order to subject the winder shaft to a despreading load apiston-cylinder unit which is rotationally fixed but axiallydisplaceable with respect to the stationary winder housing, a pressurespring constantly holding the segments in the spread state, and thedisplacing drive consisting of a piston-cylinder unit by means of whichthe winder shaft can be loaded in such a manner that it is displacedaxially.

EP 0 504 296 B1 discloses a winder for winding and/or unwinding metalstrips with strip traction forces between 10 kN and 1000 kN, consistingof a spreadable winding drum which is supported by a hollow shaftmounted in two places in a stand and can be actuated via a driving rodwhich runs through the hollow shaft by an actuating cylinder which isarranged on the hollow shaft. Coupled to the hollow shaft is a drivemotor which is arranged between the two supports of the hollow shaft andconsists of a stator and a rotor. The hollow shaft forms the rotor shaftand the driving rod forms the winding drum shaft which is mounted in thehollow shaft.

German Laid-Open Specification 1 777 229 describes a spreadable windermandrel for winding strip-shaped rolled material, in particularhot-rolled strips, with an inner mandrel body and a plurality ofspreading segments placed on the mandrel body. These spreading segmentsare supported via tappets on wedge faces of a wedge rod which is mountedconcentrically in the mandrel body and has a number of wedge faces, withthe spreading segments being connected by Jugs to a wedge rod which ismounted concentrically in the mandrel body.

DE 30 28 607 C2 discloses a rolled strip winder which already has apunch which is pretensioned by spring force, held in the spread positionand can be loaded by means of an actuator which is arranged in astationary and rotationally rigid manner in such a manner that thesegments can be despread.

Other winder systems are disclosed in GB 948,419 and U.S. Pat. No.4,433,814.

JP 051 54 552, JP 2001 252 716, JP 03 275 255 and JP 58 068 425 discloseequipping the spreading segments with magnets. In this case, however,pressure rollers and/or belt wrappers are additionally required duringinitial winding and slipping out in order to catch the strip duringinitial winding and guide the strip end. These devices cause costs inmanufacture, installation and maintenance. Furthermore, these devicesmake it more difficult to check the strip as it exits the rollingtrain/rolling stand. The disadvantage of the known embodiments is thatadditional lines are let into the shells in order to generate themagnetic force. The windings are exposed and corroded over time as aresult of the shells being abraded and the surfaces being reground. Inthe event of a shell breaking, the magnetic force ceases immediately.

The invention is therefore based on the object of simplifying the known,expensive designs and avoiding the above-mentioned disadvantages. Inaddition, the service life of the spreading segments is to be increasedand the adjustability of the holding force is to be improved.Furthermore, a device is to be created which requires only a smalloutlay on its construction as a result of the use of as few parts aspossible.

This object is achieved according to the invention in that in a windermandrel with radially movable spreading segments which are arranged onthe periphery, a mandrel body and a pulling rod, the spreading segmentsand/or the mandrel body and/or the pulling rod are configured asmagnets. This means that belt wrappers and strip pressure rollers can bedispensed with when winding the strip.

Further refinements of the winder mandrel can be found in the subclaimsrelating to this.

The invention also relates to a method for operating a winder mandrelwith radially movable spreading segments which are arranged on theperiphery, a mandrel body and a pulling rod, with the spreading segmentsand/or the mandrel body and/or the pulling rod being configured aselectromagnets and the supply voltage of the electromagnets beingswitched on during initial winding of the beginning of the strip,lowered during rolling and raised again when the strip is slipped out.This saves energy. The supply voltage is lowered to a fraction or tozero depending on the properties of the strip.

The use of magnets with regulated magnetic force as spreading segmentsor mandrel bodies or pulling rods means the use of pressure rollers andbelt wrappers is avoided. During initial winding, a greater magneticforce is provided. The strip is caught and wound on. The magnetic forcecan be reduced or switched off during rolling, since the windings of thecoil are wound fixedly and are not expected to slip. To slip the stripout, the magnetic force is increased again. The end of the strip thuslies against the coil and can be rotated into a coil lifter.

In order to prevent the rolled up strip from being magnetised, themagnetic field is reverse-polarised after the rolling process andshortly before pulling the coil off the winder mandrel.

Current is supplied to the magnetic components spreading segments ormandrel body or pulling rod by means of a converter. The converterprovides an electric current which can be variably adjusted. This isused to influence the magnetic force. Three different methods can beused to supply the spreading segments with electric current:

-   1. Supply on the drive side by means of slip rings. To this end, a    cable is guided through the pulling rod with the aid of a milled    section. Spreading segments are connected with plug-type connectors.-   2. Supply on the operation side directly in the vicinity of the    respective spreading segment by means of slip rings. An arrangement    of this type must be protected mechanically against being struck by    the strip in the event of the strip tearing.-   3. The energy is transmitted to the spreading segments by means of    induction loops. A contactless transmission of this type is possible    on the operation side and must be protected as under point 2.

Winder mandrels in which the spreading segments or the mandrel body orthe pulling rod are configured as magnets can be installed directly orsubsequently (in exchange) in pay-off reels, tension reels, reversingwinders, inspection winders, double spreading head winders.

A further advantage of the winder mandrel according to the inventionconsists in the straightforward mechanical conversion of existing plant,for example TCM, SPM, CCM, RCM and CSP, for rolling magnetisablematerials, since only the winder mandrel has to be exchanged. In newplant, investment costs for belt wrappers, strip pressure rollers andhall foundations are saved.

An exemplary embodiment of the invention is described in more detailusing a very schematic drawing. In the figures,

FIG. 1 shows a winder mandrel with spreading segments, mandrel body andpulling rod in a longitudinal section; and

FIG. 2 shows the winder mandrel in cross section.

FIG. 1 shows a longitudinal section of a winder mandrel 1 which hasspreading segments 2, a mandrel body 3 and a pulling rod 4. Thespreading segments 2 are positioned radially by means of the pulling rod4. The spreading segments 2 form in a radial outer position a circularperiphery.

The electrical voltage is transmitted by means of a slip ring 5 which isconnected to the pulling rod 4. If the pulling rod 4 or the mandrel body3 are configured as magnets, greater magnetisation forces must be takeninto account since the spreading segments 2 must also be magnetised.

FIG. 2 shows the winder mandrel in cross section.

LIST OF REFERENCE SYMBOLS

1. Winder mandrel

2. Spreading segment

3. Mandrel body

4. Pulling rod

5. Slip ring

1-4. (canceled)
 5. A method for operating a winder mandrel (1) withradially movable spreading segments (2) which are arranged on theperiphery, a mandrel body (3) and a pulling rod (4), characterized inthat the spreading segments (2) and/or the mandrel body (3) and/or thepulling rod (4) are configured as electromagnets, and that the supplyvoltage of the electromagnets is switched on during initial winding ofthe beginning of the strip, lowered during the rolling and raised againwhen the strip is clipped out.
 6. A method according to claim 5,characterized in that the supply voltage is reduced partially or to zerodependent on characteristics of a strip.